Low-bit-rate voice transmission based on transversal block coding
D. Esteban, Jean Menez · The Journal of the Acoustical Society of America · 1976
A low-bit-rate voice coding scheme, in the range of 10 to 20 KPS, based on predictive transversal block coding is described. This voice coding scheme assumes the use of short- and long-term linear prediction and an optimum PCM/DPCM block companding quantizer which ensures the same dynamic as a standard PCM companded law. It accommodates various data rates by simply modifying the number of bits allocated to the quantizer. Examples based on 8-kHz sampling rate and data rates of 8 to 16 KBPS are investigated. It is shown that a two-bit coding scheme at 20 KBPS provides a quality and intelligibility which is quite the same as the standard A-law 84-KBPS coding scheme and that with one-bit coding at 12 KBPS the quality degradation is practically not noticeable in telephony applications. Tape recordings of the investigated cases will be played at the conference.